What is Tax efficiency preference?

Tax efficiency preference controls how freely the optimizer can place assets across accounts for tax efficiency while keeping your overall portfolio mix the same. At Target allocation only, every account stays locked to the mix. At Maximum tax efficiency, individual accounts may look very different (for example bonds concentrated in brokerage and equities in retirement accounts) as long as the Total Portfolio still hits the target mix (here, a 60/40 example). The other preferences sit between those poles. The green band marks the portfolio mix; bar colors match equities and fixed income elsewhere in the product.